1. Field of the Invention
The present invention relates to a probe card of semiconductor inspection equipment. More particularly, the present invention relates to a needle fixture of the probe card and a needle fixing method to the probe card using an adhesive wherein the configuration of the needle fixture is changed to strengthen the attachment of the probe needle.
2. Description of the Related Art
In general, a semiconductor memory device is produced by performing two processes. First, a fabrication process for patterning the semiconductor memory device on a wafer is performed. Subsequently, an assembly process for assembling each semiconductor memory device on the wafer to each chip is performed. In addition, before performing the assembly process, an electric die sorting (EDS) process is performed to inspect an electric characteristic of each chip included in a wafer.
In operation, inspection equipment of the EDS process applies an electric signal to each chip on the wafer, and determines whether each chip is a pass, i.e., a good chip, or a fail, i.e., a bad chip, by inspecting the electric signal. Accordingly, the EDS process is able to identify each bad chip fabricated on the wafer. Most inspection equipment includes a probe card having a needle for applying the electric signal to the chip on the wafer. A semiconductor chip (device) determined to be a good chip in the test using the probe card is produced as a final product through a subsequent package process.
During the electric characteristic inspection of a chip of a semiconductor wafer, a needle of a probe card is contacted with an electrode pad of the semiconductor wafer, a measuring current is passed through the needle, and an electric characteristic is measured. Therefore, to measure the electric characteristic of the electrode pad on the wafer accurately, precise contact between the needle and the electrode pad is required.
When a semiconductor chip is tested using a conventional probe card, to ensure the operation reliability, i.e., whether the chip is functional, the temperature of the stage loading a wafer is varied from −40° C. to +125° C. In a conventional probe card, the probe needle is affixed to the needle fixture using an adhesive, such as a synthetic resin. Therefore, due to the temperature variation, the adhesion unit repeatedly contracts and expands, thereby generating a crack in the adhesion unit and thereby causing the probe needle to separate from the needle fixture. As a result, the reliability of the chip test is diminished. Moreover, changing a probe card after the adhesion unit becomes cracked or the probe needle has separated from the needle fixture increases production costs.